Fig. 1: The paralysis duration of the gastrocnemius (GC) muscles induced by botulinum toxin-A (BTX) is extended by anti-insulin-like growth factor 1 receptor (IGF1R) antibody.

A Representative images of western blot analysis of IGF signaling pathway in mouse GC muscle 2 weeks after saline or BTX injection. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is used as a loading control. B Quantification of IGF1R, phosphorylated IGF1R, IGF-I, and IGF-II protein levels in comparison to GAPDH protein levels. Values are presented as the mean ± standard error of the mean (SEM). **P < 0.01, ***P < 0.001, and ****P < 0.0001, analyzed using two-tailed unpaired Student’s t-test (N = 4 per group). Representative footprint analysis of naïve (C) or BTX- injected (D) mice. E Enlarged view of footprints shown in D and the formula for calculating the tibial functional index (TFI) (−100% indicates complete paralysis, and 0% indicates an intact muscle) are shown. Time schedule of the footprint test and single (F) or sequential (G) antibody administration (20 µg) after saline or BTX (F, 2.5 U; G, 1.25 U) treatment at the beginning. Control IgG antibody treatment is represented as cont IgG and anti-IGF1R antibody treatment as IGF1R. Values are presented as the mean ± SEM. *P < 0.05, ***P < 0.001, ****P < 0.0001, and ^‡P < 0.01, analyzed using two-way analysis of variance followed by post-hoc Tukey’s test (N = 3 or 4 per group).